CN102041442A - Low-alloy Q345E medium plate and production process thereof - Google Patents
Low-alloy Q345E medium plate and production process thereof Download PDFInfo
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- CN102041442A CN102041442A CN2010105976638A CN201010597663A CN102041442A CN 102041442 A CN102041442 A CN 102041442A CN 2010105976638 A CN2010105976638 A CN 2010105976638A CN 201010597663 A CN201010597663 A CN 201010597663A CN 102041442 A CN102041442 A CN 102041442A
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Abstract
The invention discloses a low-alloy Q345E medium plate produced without adding micro-alloy element and a production process thereof. The low-alloy Q345E medium plate comprises the following chemical components in percentage by weight: 0.13-0.19% of C, 0.20-0.50% of Si, 1.30-1.60% of Mn, less than or equal to 0.020% of P, less than or equal to 0.010% of S, 0.015-0.050% of Als, and the balance of Fe and residual elements. The process disclosed by the invention comprises the following steps: KR (knotted reactor) hot metal pretreatment of high-quality hot metal, processing with a top-bottom combined blowing converter, LF ((ladle furnace) refining, casting blank stack cooling, processing with a heating furnace, rolling, ACC (accelerated cooling) laminar flow cooling, processing with a hot straightener, stack cooling, finishing, external inspection, flaw detection and storage. The invention has the beneficial effects that: compared with the traditional Q345E, precious alloys such as Nb, Ti and the like are not added without changing the carbon equivalent, all performance indexes of Q345E are guaranteed, and the production cost is remarkably reduced.
Description
Technical field
The present invention relates to Heavy Plate Production, be specifically related to a kind of employing and do not add microalloy element production low-alloy Q345E steel plate and production technique thereof.
Background technology
Current international financial crisis has caused bigger impact to Iron and Steel Enterprises in China; particularly the plate of moderate thickness industry of steel mill is the comparatively serious industry that is hit; for tackling the disadvantageous effect that international financial crisis brings; accelerate restructuring; promote industrial upgrading; realize low cost strategy, strengthen enterprise competitiveness and have a very important role.At present, domestic production low-alloy Q345D-Z35 steel plate producer is few, because it in process of production, adds microalloy elements such as Nb, V, Ti, the production cost height; Complex process.
Summary of the invention
Disadvantageous effect for the reply international financial crisis brings realizes low cost strategy, strengthens enterprise competitiveness.The inventor has obtained a kind of technology of not adding any microalloy element production low-alloy Q345E steel plate, thereby has finished the present invention through groping.
Therefore, the object of the present invention is to provide a kind of a kind of low-cost Q345E steel plate that provides.
Another object of the present invention is to reduce production costs and produce the technology of Q345E steel plate.
For achieving the above object, the technical scheme that the present invention takes is: this low-alloy Q345E steel plate comprise following chemical components in mass percent (unit, wt%): C:0.13～0.19, Si:0.20～0.50, Mn:1.30～1.60, P≤0.020, S≤0.010, Als:0.015～0.050, other is Fe and relict element;
Carbon equivalent [Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15] :≤0.46.
In the preceding method, the steel plate thickness of being produced is 60mm and following specification.
For obtaining above-mentioned steel plate, technical process of the present invention is: high-quality molten iron, KR hot metal pretreatment, top and bottom combined blown converter, the refining of LF stove, strand cooling in heap, process furnace, rolling, ACC laminar flow cooling, thermal straightening machine, cooling in heap, finishing, outer inspection, flaw detection, warehouse-in; In refinement step, omnidistance Argon adds refining slag, basicity is by 4.0～6.0 controls, and heat-up time, one heating, 7～12min, two heated 6～10min by twice control, add silicon-calcium wire before leaving from station, must close argon gas, 1565 ± 15 ℃ of last steel temperature before adding silicon-calcium wire; In rolling step, the recrystallize final temperature of steel is 895 ℃, and the steel gauge control of drying in the air is at 2.5～4 times of finished product thickness, and finishing temperature is controlled at 780～840 ℃; Roll the back and adopt the laminar flow cooling, return red temperature between 640～700 ℃; In the cooling in heap step, the stacking slow cooling temperature is not less than 400 ℃, cooling in heap time 〉=24 hour.
The present invention is on the composition basis of original Q345E low alloy steel, suitably adjust the content composition and division in a proportion example of C, Mn among the Q345E, and P, S etc. influence the harmful element content of steel plate plasticity and toughness in the simultaneously strict control steel, and then do not add price high microalloy element Nb, V etc., thereby guaranteed the ballistic work of Q345E steel plate, guaranteed the intensity and the plasticity coupling of steel plate simultaneously again.
In smelting process, P(phosphorus in the strict control steel), S(sulphur) wait harmful element, the purity of assurance molten steel reaches the Clean Steel level substantially.In follow-up rolling heat-processed, thick for preventing inside steel billet crystal grain, suitably reduce Heating temperature, be steel billet crystal grain thinning establish a firm foundation in the operation of rolling.In the operation of rolling,, can guarantee Q345E plate property demand by adopting domestic advanced person's TMCP rolling technique.
Beneficial effect of the present invention is: compare with traditional Q345E, under the constant situation of carbon equivalent, do not add valuable alloys such as Nb, V, guarantee the every performance index of Q345E, greatly reduce production cost.
Embodiment
Low-alloy Q345E steel plate of the present invention comprise following chemical components in mass percent (unit, wt%): C:0.13～0.19, Si:0.20～0.50, Mn:1.30～1.60, P≤0.020, S≤0.010, Als:0.015～0.050, other is Fe and relict element;
Carbon equivalent [Ceq=C+Mn/6+ (Cr+Mo+V)/5+ (Ni+Cu)/15] :≤0.46.
In the preceding method, the steel plate thickness of being produced is 60mm and following specification.
Technical process of the present invention is: high-quality molten iron, KR hot metal pretreatment, top and bottom combined blown converter, the refining of LF stove, strand cooling in heap, process furnace, rolling, ACC laminar flow cooling, thermal straightening machine, cooling in heap, finishing, outer inspection, flaw detection, warehouse-in; In refinement step, omnidistance Argon adds refining slag, basicity is by 4.0～6.0 controls, and heat-up time, one heating, 7～12min, two heated 6～10min by twice control, add silicon-calcium wire before leaving from station, must close argon gas, 1565 ± 15 ℃ of last steel temperature before adding silicon-calcium wire; In rolling step, the recrystallize final temperature of steel is 895 ℃, and the steel gauge control of drying in the air is at 2.5～4 times of finished product thickness, and finishing temperature is controlled at 780～840 ℃; Roll the back and adopt the laminar flow cooling, return red temperature between 640～700 ℃; In the cooling in heap step, the stacking slow cooling temperature is not less than 400 ℃, cooling in heap time 〉=24 hour.
Embodiment is as follows:
1, composition design
On the composition basis of traditional Q 345E low alloy steel, to smelt by Clean Steel, strict control P, S content do not add microalloy Nb, V, by carrying out strict rolling low-carbon-equivalent and the weldability that had both guaranteed steel plate of TMCP, ensure Q345E obdurability coupling again.
Concrete composition design is as follows:
C:0.13～0.19, Si:0.20～0.50, Mn:1.30～1.60, P :≤0.020, S :≤0.010, AlS:0.015～0.050, other is Fe and relict element;
2, KR hot metal pretreatment technology
Before the molten iron that arrives at a station must be taken off slag with take off the back slag, guarantee liquid level thickness of slag layer≤20mm, molten iron guarantees molten iron S≤0.005% after the KR stirring desulphurization, assurance desulfurization cycle≤21min, desulfurization temperature drop≤20 ℃.
, converter smelting process
Go into stove molten iron S≤0.005%, P≤0.080%, molten iron temperature 〉=1250 ℃, molten iron Intake Quantity error is controlled by ± 1t, the strict high-quality scrap stock that adopt of steel scrap, process rifle position is by early stage 1.0～1.3m, mid-term 1.2～1.6m, later stage 1.0～1.1m control, slag making basicity R is by 2.5～4.0 controls, tapping target P≤0.015%, C 〉=0.05%, S≤0.012%, in the tapping process in ladle Si-Al-Ba-Ca, manganeseirom, ferro-silicon and lime, fluorite.With slag tapping before the floating plug retaining, must adopt the slag stop cone pushing off the slag before tapping finishes before the tapping, guarantee thickness of slag layer≤30mm, require omnidistance Argon in the converter tapping process.
, argon blowing process
The disposable adding aluminum steel in argon station requires strong Argon 3min at the argon station, flow 200～500NL/min, and molten steel face bore hole diameter is controlled at 300～600mm, must not be lower than 1570 ℃ from argon station temperature.
, the LF refinery practice
Omnidistance Argon in the refining process, Argon intensity is regulated according to different link needs.
Add refining slag, basicity press 4.0-6.0 and is controlled, and the refinement and deoxidation agent is based on calcium carbide, aluminum shot, ferrosilicon powder, and add-on is according to oxygen level in the molten steel and make the white slag situation and add in right amount.Heat-processed selects suitable electric current to heat according to rhythm is more than needed with temperature conditions, heat-up time, one heating, 7～12min, two heating, 6～10min required in two heat-processedes according to the slag making situation by twice control, add reductor, and require the dry slag number of times greater than 6 times.Add silicon-calcium wire before leaving from station, must close argon gas, 1565 ± 15 ℃ of last steel temperature (not adopting vacuum outgas)/1610 ± 15 ℃ (employing vacuum outgas) before adding silicon-calcium wire.
, continuous casting process
Guarantee that the casting machine status of equipment is good before watering steel; 15 ± 10 ℃ of middle bag superheating temperature; pulling rate: 0.7m/min; specific water: 0.80L/ ㎏; electricity stirs: 900A, 5Hz, 30s-3-30s; continuous-casting steel pouring requires the whole process protection casting, unwraps greatly and waters necessary cover protective tube in the 1min of back, must guarantee not show of molten steel face in the middle bag casting process.Rationally control stopper Argon amount in the steel pouring process, guarantee that liquid level fluctuation of crystallizer is slight.After rolling off the production line, strand requires cooling in heap 〉=12h.
, the heating
Heating temperature and heat-up time are as follows: 900～1100 ℃ of preheating section temperature, 1200～1240 ℃ of heating zone temperature, 1200～1220 ℃ of holding-zone temperature, rate of heating 10～13min/cm;
8, controlled rolling and controlled cooling:
In conjunction with the steel-making chemical ingredients, through theoretical calculation, the recrystallize final temperature of steel is 895 ℃, and is thick for preventing mixed crystal and crystal grain, therefore designs it and treats that temperature is dried in the air and begin finish rolling below the steel to 880 ℃.The steel gauge control of drying in the air is at 2.5～3 times of finished product thickness, for finish rolling stage accumulative total deflection and crystal grain thinning, dislocations strengthening lay the foundation;
As slow cooling easily makes grain growth after rolling, and the alloy solid solution amounts such as C, Mn in the tissue are limited, therefore will control suitable speed of cooling.In order to obtain good comprehensive mechanical property, according to the difference of thickness of slab, roll the back and adopt different laminar flow coolings, by adjusting cooling manifold group number, guarantee to return red temperature between 650～700 ℃.
Cooling controlling and rolling controlling process is as follows:
The fs start rolling temperature is controlled between 1000～1200 ℃, and it is rolling to adopt high temperature low speed to depress greatly, and reduction in pass is not less than 20mm; When temperature is not less than 1000 ℃, stop rolling the steel that dries in the air, the steel thickness that dries in the air is 2.5-3 times of finished product thickness; When rolled piece temperature during less than 880 ℃, the beginning subordinate phase is rolling, two-stage accumulative total deformation rate 〉=60%, and finishing temperature is controlled at 780～840 ℃; The rolling back that finishes adopts the ACC control cold, and final cooling temperature is controlled between 650～700 ℃, is sent to the straightener aligning then.
, cooling in heap technology
Adopt high temperature cooling in heap technology can effectively avoid to reduce the content of hydrogen in the steel plate simultaneously greatly, fully realize thermal diffusion effect, improve the steel plate inspection defective because of cooling off the unrelieved stress that produces fast.Steel plate stacking slow cooling technology is as follows; The stacking slow cooling temperature is not less than 400 ℃, and the cooling in heap time was controlled at 24 hours;
11, interpretation of result
11.1 mechanical mechanics property analysis
Composition and mechanical mechanics property are pressed GB/T1591-2008 and are carried out, and specifically see Table 1.
Table 1 Q345E steel plate mechanical mechanics property
The thick Q345E of this trial production 20～60mm amounts to 30 batches, and wherein: yield strength is controlled at 340～450 MPa, has on average reached 375 MPa, than the rich 40MPa of standard; Tensile strength is controlled at 500～590 MPa, has on average reached 536 MPa, than the rich 46MPa of standard; Elongation is controlled at 25%-32%, on average reaches 29%, than standard affluence 8%;-40 ℃ of V-type ballistic works are controlled at 79～270J, have on average reached 152 J, reach the level of Q345E fully.
Outer inspection and flaw detection
The steel plate of being developed is examined outward, and the percentage of A-class goods 100% is detected a flaw by JB/T 2970-2004, and unification level rate is 60%, and closing three grades of rates is 100%, has reached desired result.
Claims (2)
1. low-alloy Q345E steel plate, this low-alloy Q345E steel plate comprises following chemical components in mass percent, and (unit, wt%): C:0.13～0.19, Si:0.20～0.50, Mn:1.30～1.60, P≤0.020, S≤0.010, Als:0.015～0.050, other is Fe and relict element.
2. production method of low-alloy Q345E steel plate according to claim 1, this production method may further comprise the steps: high-quality molten iron, KR hot metal pretreatment, top and bottom combined blown converter, the refining of LF stove, strand cooling in heap, process furnace, rolling, ACC laminar flow cooling, thermal straightening machine, cooling in heap, finishing, outer inspection, flaw detection, warehouse-in; It is characterized in that in refinement step omnidistance Argon adds refining slag, basicity is by 4.0～6.0 controls, and heat-up time, one heating, 7～12min, two heated 6～10min by twice control, add silicon-calcium wire before leaving from station, must close argon gas, 1565 ± 15 ℃ of last steel temperature before adding silicon-calcium wire; In rolling step, the recrystallize final temperature of steel is 895 ℃, and the steel gauge control of drying in the air is at 2.5～4 times of finished product thickness, and finishing temperature is controlled at 780～840 ℃; Roll the back and adopt the laminar flow cooling, return red temperature between 640～700 ℃; In the cooling in heap step, the stacking slow cooling temperature is not less than 400 ℃, cooling in heap time 〉=24 hour.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102312156A (en) * | 2011-07-08 | 2012-01-11 | 南阳汉冶特钢有限公司 | Guaranteed performance and low alloy Q345E+B steel plate of less than 60mm and production process thereof |
| CN102424933A (en) * | 2011-12-02 | 2012-04-25 | 山西太钢不锈钢股份有限公司 | Hot-rolled high-strength strip steel and manufacturing method thereof |
| CN102676921A (en) * | 2012-05-04 | 2012-09-19 | 武汉钢铁(集团)公司 | Cold-resistant high-strength hot-rolled angle steel and production method thereof |
| CN103451520A (en) * | 2013-09-25 | 2013-12-18 | 武汉钢铁(集团)公司 | Q345 engineering steel and production method thereof |
| CN103540836A (en) * | 2013-08-23 | 2014-01-29 | 安阳钢铁股份有限公司 | Steckle mill ultra-wide and heavy steel plate with high toughness and low alloy and production process thereof |
| CN104018063A (en) * | 2014-06-18 | 2014-09-03 | 内蒙古包钢钢联股份有限公司 | Low alloy and high strength Q420C medium steel plate and production method thereof |
| CN111139405A (en) * | 2020-03-10 | 2020-05-12 | 唐山中厚板材有限公司 | Production method of low-cost short-process flaw detection-guaranteed medium plate |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101871083A (en) * | 2010-06-14 | 2010-10-27 | 南阳汉冶特钢有限公司 | Ultra-thick low-alloy high-strength Q345-series steel plate and production method thereof |
| CN101876000A (en) * | 2009-11-18 | 2010-11-03 | 秦皇岛首秦金属材料有限公司 | Method for producing high-toughness ultra-thick plate by using continuous casting blank |
-
2010
- 2010-12-21 CN CN2010105976638A patent/CN102041442A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101876000A (en) * | 2009-11-18 | 2010-11-03 | 秦皇岛首秦金属材料有限公司 | Method for producing high-toughness ultra-thick plate by using continuous casting blank |
| CN101871083A (en) * | 2010-06-14 | 2010-10-27 | 南阳汉冶特钢有限公司 | Ultra-thick low-alloy high-strength Q345-series steel plate and production method thereof |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102312156A (en) * | 2011-07-08 | 2012-01-11 | 南阳汉冶特钢有限公司 | Guaranteed performance and low alloy Q345E+B steel plate of less than 60mm and production process thereof |
| CN102424933A (en) * | 2011-12-02 | 2012-04-25 | 山西太钢不锈钢股份有限公司 | Hot-rolled high-strength strip steel and manufacturing method thereof |
| CN102676921A (en) * | 2012-05-04 | 2012-09-19 | 武汉钢铁(集团)公司 | Cold-resistant high-strength hot-rolled angle steel and production method thereof |
| CN102676921B (en) * | 2012-05-04 | 2014-04-09 | 武汉钢铁(集团)公司 | Cold-resistant high-strength hot-rolled angle steel and production method thereof |
| CN103540836A (en) * | 2013-08-23 | 2014-01-29 | 安阳钢铁股份有限公司 | Steckle mill ultra-wide and heavy steel plate with high toughness and low alloy and production process thereof |
| CN103451520A (en) * | 2013-09-25 | 2013-12-18 | 武汉钢铁(集团)公司 | Q345 engineering steel and production method thereof |
| CN104018063A (en) * | 2014-06-18 | 2014-09-03 | 内蒙古包钢钢联股份有限公司 | Low alloy and high strength Q420C medium steel plate and production method thereof |
| CN111139405A (en) * | 2020-03-10 | 2020-05-12 | 唐山中厚板材有限公司 | Production method of low-cost short-process flaw detection-guaranteed medium plate |
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Application publication date: 20110504 |